House Speaker Paul Ryan says he is concerned that Donald Trump is not advancing their party's principles. He joins numerous other Republicans in distancing themselves from the likely GOP presidential nominee. Political Reporter Josh Robin has more.

He's the pick of Republican voters, but not the party's most influential leaders.

"It's time to set aside bullying, to set aside belittlement, and to appeal to higher aspirations," House Speak Paul Ryan (R) said.

But Donald Trump says he's not ready to sign on with Ryan.

"Perhaps in the future we can work together and come to an agreement about what is best for the American people," Trump said in a statement. "They have been treated so badly for so long that it is about time for politicians to put them first!"

Ryan headlines a who's-who of Republican luminaries who are saying, either we'll see or no thanks to backing the New York native.

Former Presidents George H.W. and George W. Bush aren't going to the convention in Cleveland.

The 1996 nominee Bob Dole is reportedly going, but he isn't committed to backing Trump.

That's more than can be said for the 2008 nominee John McCain; the Arizona senator was reportedly taped fretting to fundraisers how Trump could jeopardize his reelection bid.

And the one from 2012?

"Donald Trump is a phony, a fraud," Mitt Romney said. "His promises are as worthless as a degree from Trump University."

Romney isn't going, either.

Trump doesn't seem to care, especially about the presidents Bush, father and brother of Jeb Bush.

"They just say I was very nasty to him," Trump said. "Well, I was. I came up with a low-energy individual — you know, whatever he is, I think he is."

Some of the Republican elites back Trump — Senate Majority Leader Mitch McConnell, for instance, as well as the party's chair.

But considering Congress's approval rating is even lower than Trump's, it may be to Trump's advantage to continue attacking party leaders.

"I think there's a huge disconnect between the D.C. establishment and the folks out in the grassroots," Republican political strategist Marc Rotterman said. "I think Mr. Trump tapped into that. I don't think endorsements mean that much."

All this comes as Trump sent out a head-scratching tweet, seen below, in an apparent bid to overcome a 65 percent favorability gap recently found among Latinos: